Firewalls

By Chris DeGeare

What is a Firewall?

A firewall is a hardware device or software package that protects the resources on a private network from users on the Internet. This is accomplished by monitoring all network transmissions coming in and out of the private network and comparing that traffic to a set of rules or policies. If the network traffic matches a rule or policy, it is either allowed to pass or it is blocked, depending upon whether the firewall policy identifies the traffic as harmful or acceptable.

Example:
If the firewall is configured to block all P2P (Peer-to-peer) traffic, and someone outside the private network tries to access your computer using P2P, the traffic will automatically be blocked by the firewall. Similarly, if there is no policy set with regards to P2P, the traffic will be allowed to pass.

Types of Firewalls

As mentioned earlier, firewalls can be either hardware devices or software. Both are effective security solutions, but there are some differences between the two.

Hardware Firewalls
Electronic devices that separate your network from the Internet are called Hardware Firewalls. These devices are physically located at the gateway to the Internet, which is usually your cable/DSL modem. This physical device monitors all traffic coming in and out of your private network and blocks dangerous traffic. Linksys is a leading manufacturer of home networking products including hardware firewalls. Hardware Firewalls are very useful if you have a home network in which multiple computers share one Internet connection. A single hardware firewall will protect all of the computers inside the home network.

Software Firewalls
Computer software that is designed to allow or block traffic coming in and out of your personal computers is known as a Software Firewall. There are many software firewalls available, but some of the more popular are Kerio WinRoute Firewall, Zone Alarm, and SoftPerfect. Personal Firewalls are very effective security solutions, but they only protect the individual computer on which the firewall is installed.

Example:
If you have three computers on your personal network, you either need to install three software firewalls, or one hardware firewall.

Protecting your computers and network with a firewall is a low-cost way to greatly reduce the chance of being a victim of computer intrusion and data/identity theft.